Antarctica’s Ross Ice Shelf is the world’s largest floating slab of ice: it’s about the size of Spain, and nearly a kilometre thick.

The ocean beneath, roughly the volume of the North Sea, is one of the most important but least understood parts of the climate system.

We are part of the multi-disciplinary Aotearoa New Zealand Ross Ice Shelf programme team, and have melted a hole through hundreds of metres of ice to explore this ocean and the ice shelf’s vulnerability to climate change. Our measurements show that this hidden ocean is warming and freshening – but in ways we weren’t expecting.

Instruments travelling 360m down a bore hole, from the snow-covered surface of the Ross Ice Shelf through to the ocean below the ice. After splash-down at about 60m, they move through the bubble-rich upper ice and down into the dark bubble-free lower reaches of the ice – passing embedded sediment that left the coast line centuries ago.

A hidden conveyor belt

All major ice shelves are found around the coast of Antarctica. These massive pieces of ice hold back the land-locked ice sheets that, if freed to melt into the ocean, would raise sea levels and change the face of our world.

An ice shelf is a massive lid of ice that forms when glaciers flow off the land and merge as they float out over the coastal ocean. Shelves lose ice by either breaking off icebergs or by melting from below. We can see big icebergs from satellites – it is the melting that is hidden.

Because the water flowing underneath the Ross Ice Shelf is cold (minus 1.9C), it is called a “cold cavity”. If it warms, the future of the shelf and the ice upstream could change dramatically. Yet this hidden ocean is excluded from all present models of future climate.

There has only been one set of measurements of this ocean, made by an international team in the late 1970s. The team made repeated attempts, using several types of drills, over the course of five years. With this experience and newer, cleaner, technology, we were able to complete our work in a single season.

Our basic understanding is that seawater circulates through the cavity by flowing in at the sea bed as relatively warm, salty water. It eventually finds its way to the shore – except of course this is a shoreline under as much as 800 metres of ice. There it starts melting the shelf from beneath and flows across the shelf underside back towards the open ocean.

Peering through a hole in the ice

The New Zealand team – including hot water drillers, glaciologists, biologists, seismologists, oceanographers – worked from November through to January, supported by tracked vehicles and, when ever the notorious local weather permitted, Twin Otter aircraft.

As with all polar oceanography, getting to the ocean is often the most difficult part. In this case, we faced the complex task of melting a bore hole, only 25 centimetres in diameter, through hundreds of metres of ice.

A team of ice drillers from Victoria University of Wellington used hot water and a drilling system developed at Victoria to melt a hole through hundreds of metres of ice.Craig Stevens, CC BY-ND

But once the instruments are lowered more than 300m down the bore hole, it becomes the easiest oceanography in the world. You don’t get seasick and there is little bio-fouling to corrupt measurements. There is, however, plenty of ice that can freeze up your instruments or freeze the hole shut.

A moving world

Our camp in the middle of the ice shelf served as a base for this science, but everything was moving. The ocean is slowly circulating, perhaps renewing every few years. The ice is moving too, at around 1.6 metres each day where we were camped. The whole plate of ice is shifting under its own weight, stretching inexorably toward the ocean fringe of the shelf where it breaks off as sometimes massive icebergs. The floating plate is also bobbing up and down with the daily tides.

Things also move vertically through the shelf. As the layer stretches toward the front, it thins. But the shelf can also thicken as new snow piles up on top, or as ocean water freezes onto the bottom. Or it might thin where wind scours away surface snow or relatively warm ocean water melts it from below.

When you add it all up, every particle in the shelf is moving. Indeed, our camp was not so far (about 160km) from where Robert Falcon Scott and his two team members were entombed more than a century ago during their return from the South Pole. Their bodies are now making their way down through the ice and out to the coast.

What the future might hold

If the ocean beneath the ice warms, what does this mean for the Ross Ice Shelf, the massive ice sheet that it holds back, and future sea level? We took detailed temperature and salinity data to understand how the ocean circulates within the cavity. We can use this data to test and improve computer simulations and to assess if the underside of the ice is melting or actually refreezing and growing.

We also discovered that the underside of the ice was rather more complex than we thought. It was covered in ice crystals – something we see in sea ice near ice shelves. But there was not a massive layer of crystals as seen in the smaller, but very thick, Amery Ice Shelf.

Instead the underside of the ice held clear signatures of sediment, likely incorporated into the ice as the glaciers forming the shelf separated from the coast centuries earlier. The ice crystals must be temporary.

None of this is included in present models of the climate system. Neither the effect of the warm, saline water draining into the cavity, nor the very cold surface waters flowing out, the ice crystals affecting heat transfer to the ice, or the ocean mixing at the ice fronts.

It is not clear if these hidden waters play a significant role in how the world’s oceans work, but it is certain that they affect the ice shelf above. The longevity of ice shelves and their buttressing of Antarctica’s massive ice sheets is of paramount concern.

Craig Stevens, Associate Professor in Ocean Physics and Christina Hulbe, Professor and Dean of the School of Surveying (glaciology specialisation)

At a time when the effects of climate change are accelerating and published science overwhelmingly supports the view that humans are responsible for the rate of change, powerful groups remain in denial across politics, the media, and industry. Now more than ever, we need scientists and policymakers to work together to create and implement effective policy which is informed by the most recent and reliable evidence.

We know that trust between scientists and policymakers is important in developing policy that is informed by scientific evidence. But how do you build this trust, and how do you make sure that it genuinely leads to positive outcomes for society?

In response to these questions, our recent Perspective in Nature Climate Change explores the dynamics of trust at the interface of climate science and policy.

We suggest that while trust is an important component of the science-policy dynamic, there can be such a thing as “too much” trust between scientists and policymakers.

Understanding this dynamic is crucial if we are to deliver positive outcomes for science, policy, and the society that depends on their cooperation.

What happens when there is ‘too much’ trust?

Trust between climate scientists (researchers in a range of disciplines, institutions, and organisational settings) and policymakers (civil servants in government departments or agencies who shape climate policy) is useful because it enhances the flow of information between them. In a trusting relationship, we can expect to see a scientist explaining a new finding directly to a policymaker, or a policymaker describing future information needs to a scientist.

Think about a hypothetical situation in which a scientist and policy-maker come to trust each other deeply. What happens if one of them starts to become loose with the facts, or fails to adhere to professional standards? Is their trusting counterpart more, or less, likely to identify the poor behaviour and respond appropriately?

Over time, a trusting relationship may evolve into a self-perpetuating belief of trustworthiness based on the history of the relationship. This is where scientists and policymakers may find themselves in a situation of “too much” trust.

We know that science advances by consensus, and that this consensus is shaped by rigorous research and review, and intense debate and scrutiny. But what if (as in the hypothetical example described above) a policy-maker’s trust in an individual scientist means they bypass the consensus and instead depend on that one scientist for new information? What happens if that scientist is – intentionally or unintentionally – wrong?

When you have “too much” trust, the benefits of trust can instead manifest as perverse outcomes, such as “blind faith” commitments between parties. In a situation like this, a policymaker may trust an individual scientist so much that they do not look for signs of misconduct, such as the misrepresentation of findings.

“Cognitive lock-in” might result, where a policymaker sticks to a failing policy because they feel committed to the scientist who first recommended the course of action. For example, state-of-the-art climate forecasting tools are available in the Pacific but are reportedly underused. This is partly because the legacy of trusting relationships between scientists and policymakers in the region has led them to continue relying on less sophisticated tools.

“Too much” trust can also lead to overly burdensome obligations between scientists and policymakers. A scientist may come to hold unrealistically high expectations of the level of information a policymaker can share, or a policymaker may desire the production of research by an unfeasible deadline.

What’s the right way to trust?

With this awareness of the potentially negative outcomes of “too much” trust, should we abandon trust at the climate science-policy interface all together?

No. But we can – and should – develop, monitor, and manage trust with acknowledgement of how “too much” trust may lead to perverse outcomes for both scientists and policy-makers.

We should aim for a state of “optimal trust”, which enjoys the benefits of a trusting relationship while avoiding the pitfalls of taking too trusting an approach.

We propose five key strategies for managing trust at the climate science-policy interface.

Be explicit about expectations for trust in a climate science-policy relationship. Climate scientists and policy-makers should clarify protocols and expectations about behaviour through open discussion as early as possible within the relationship.

Transparency and accountability, especially when things go wrong, are critical to achieving and maintaining a state of optimal trust. When things do go wrong, trust repair can right the relationship.

Implement systems for monitoring trust, such as discussion groups within scientific and policy organisations and processes of peer review. Such approaches can help to identify the effects of “too much” trust – such as capture, cognitive lock-in, or unrealistically high expectations.

Manage staff churn in policy and scientific organisations. When scientists or policy-makers change role or institution, handing over the trusting relationships can help positive legacies and practices to carry on.

Use intermediaries such as knowledge brokers to facilitate the flow of information between science and policy. Such specialists can promote fairness and honesty at the science-policy interface, increasing the probability of maintaining ‘optimal trust’.

Embracing strategies such as these would be a positive step toward managing trust between scientists and policymakers, both in climate policy and beyond.

In this time of contested science and highly politicised policy agendas, all of us in science and policy have a responsibility to ensure we act ethically and appropriately to achieve positive outcomes for society.

Keen students of climate politics might recognise November 30 as the anniversary of the opening of the historic Paris climate summit two years ago. But you might not know that today also marks 30 years since Australian scientists first officially sounded the alarm over climate change, at a conference hailed as the dawn of the ongoing effort to forecast and monitor the future climate of our continent.

November 30, 1987, marked the start of the inaugural GREENHOUSE conference hosted by Monash University and attended by 260 delegates. The five-day meeting was convened as part of a new federal government plan in response to the burgeoning global awareness of the impending danger of global warming.

The conference’s convenor, the then CSIRO senior research scientist Graeme Pearman, had approached some 100 researchers in the months leading up to the conference. He gave them a scenario of likely climate change for Australia for the next 30 to 50 years, developed with his CSIRO colleague Barrie Pittock, and asked them to forecast the implications for agriculture, farming and other sectors.

As a result, the conference gave rise to a book called Greenhouse: Planning for Climate Change, which outlined rainfall changes, sea-level rise and other physical changes that are now, three decades on, all too familiar. As the contents page reveals, it also tackled impacts on society – everything from insurance to water planning, mosquito-borne diseases, and even ski fields.

Internationally, awareness of global warming had already been building for a couple of decades, and intensifying for a couple of years. While the ozone hole was hogging global headlines, a United Nations scientific meeting in Villach, Austria, in 1985 had issued a statement warning of the dangers posed by carbon dioxide and other greenhouse gases.

Pearman wasn’t at that meeting, but he was familiar with the problem. As he wrote after the 1987 conference, the strength of the Villach statement was “hardly a surprise, as recent evidence had suggested more strongly than ever that climatic change is now probable on timescales of decades”.

…the last bloke to talk was right at the far end of the table. Very quiet gentleman… He said, ‘You’re all wrong – it’s the dial in my laboratory, and the laboratories of my colleagues around the world.’ He said, ‘Every day, we see the needle going up, because of what we call the greenhouse effect.‘

Summit success

The GREENHOUSE 87 conference was hailed as a great success, creating new scientific networks and momentum. It was what we academics like to call a “field-configuring event”.

The GREENHOUSE conferences have continued ever since. After a sporadic first couple of decades, the meetings have been held biennally around the country since 2005; the latest was in Hobart in 2015, as there wasn’t a 2017 edition.

What happened next?

The Greenhouse Project helped to spark and channel huge public interest in and concern about climate change in the late 1980s. But politicians fumbled their response, producing a weak National Greenhouse Response Strategy in 1992.

The Commission for the Future was privatised, the federal government declined to fund a follow-up to the Greenhouse Project, and a new campaign group called Greenhouse Action Australia could not sustain itself.

Meanwhile, the scientists kept doing what scientists do: observing, measuring, communicating, refining. Pittock produced many more books and articles. Pearman spoke to Paul Keating’s cabinet in 1994 while it briefly pondered the introduction of a carbon tax. He retired in 2004, having been reprimanded and asked to resign, ironically enough for speaking out about climate change.

As I’ve written previously on The Conversation, Australian policymakers have been well served by scientists, but have sadly taken little real notice. And lest all the blame be put onto the Coalition, let’s remember that one chief scientific adviser, Penny Sackett, quit mid-term in 2011, when Labor was in government. She has never said exactly why, but barely met Kevin Rudd and never met his successor Julia Gillard.

Our problem is not the scientists. It’s not the science. It’s the politics. And it’s not (just) the politicians, it’s the ability (or inability) of citizens’ groups to put the policymakers under sustained and irresistible pressure, to create the new institutions we need for the “looming global-scale failures” we face.

A South Australian coda

While researching this article, I stumbled across the following fact. Fourteen years and a day before the Greenhouse 87 conference had begun, Don Jessop, a Liberal senator for South Australia, made this statement in parliament:

It is quite apparent to world scientists that the silent pollutant, carbon dioxide, is increasing in the atmosphere and will cause us great concern in the future. Other pollutants from conventional fuels are proliferating other gases in the atmosphere, not the least of these being the sulphurous gases which will be causing emphysema and other such health problems if we persist with this type of energy source. Of course, I am putting a case for solar energy. Australia is a country that can well look forward to a very prosperous future if it concentrates on solar energy right now.

We, the undersigned scientists, are deeply concerned about the future of the Australian Marine Parks Network and the apparent abandoning of science-based policy by the Australian government.

On July 21, 2017, the Australian government released draft management plans that recommend how the Marine Parks Network should be managed. These plans are deeply flawed from a science perspective.

Of particular concern to scientists is the government’s proposal to significantly reduce high-level or “no-take” protection (Marine National Park Zone IUCN II), replacing it with partial protection (Habitat Protection Zone IUCN IV), the benefits of which are at best modest but more generally have been shown to be inadequate.

The 2012 expansion of Australia’s Marine Parks Network was a major step forward in the conservation of marine biodiversity, providing protection to habitats and ecological processes critical to marine life. However, there were flaws in the location of the parks and their planned protection levels, with barely 3% of the continental shelf, the area subject to greatest human use, afforded high-level protection status, and most of that of residual importance to biodiversity.

The government’s 2013 Review of the Australian Marine Parks Network had the potential to address these flaws and strengthen protection. However, the draft management plans have proposed severe reductions in high-level protection of almost 400,000 square kilometres – that is, 46% of the high-level protection in the marine parks established in 2012.

Commercial fishing would be allowed in 80% of the waters within the marine parks, including activities assessed by the government’s own risk assessments as incompatible with conservation. Recreational fishing would occur in 97% of Commonwealth waters up to 100km from the coast, ignoring the evidence documenting the negative impacts of recreational fishing on biodiversity outcomes.

Under the draft plans:

The Coral Sea Marine Park, which links the iconic Great Barrier Reef Marine Park to the waters of New Caledonia’s Exclusive Economic Zone (also under consideration for protection), has had its Marine National Park Zones (IUCN II) reduced in area by approximately 53% (see map below)

Six of the largest marine parks have had the area of their Marine National Park Zones IUCN II reduced by between 42% and 73%

Two marine parks have been entirely stripped of any high-level protection, leaving 16 of the 44 marine parks created in 2012 without any form of Marine National Park IUCN II protection.

The replacement of high-level protection with partial protection is not supported by science. The government’s own economic analyses also indicate that such a reduction in protection offers little more than marginal economic benefits to a very small number of commercial fishery licence-holders.

Retrograde step

This retrograde step by Australia’s government is a matter of both national and international significance. Australia has been a world leader in marine conservation for decades, beginning with the establishment of the Great Barrier Reef Marine Park in the 1970s and its expanded protection in 2004.

At a time when oceans are under increasing pressure from overexploitation, climate change, industrialisation, and plastics and other forms of pollution, building resilience through highly protected Marine National Park IUCN II Zones is well supported by decades of science. This research documents how high-level protection conserves biodiversity, enhances fisheries and assists ecosystem recovery, serving as essential reference areas against which areas that are subject to human activity can be compared to assess impact.

The establishment of a strong backbone of high-level protection within Marine National Park Zones throughout Australia’s Exclusive Economic Zone would be a scientifically based contribution to the protection of intact marine ecosystems globally. Such protection is consistent with the move by many countries, including Chile, France, Kiribati, New Zealand, Russia, the UK and US to establish very large no-take marine reserves. In stark contrast, the implementation of the government’s draft management plans would see Australia become the first nation to retreat on ocean protection.

Australia’s oceans are a global asset, spanning tropical, temperate and Antarctic waters. They support six of the seven known species of marine turtles and more than half of the world’s whale and dolphin species. Australia’s oceans are home to more than 20% of the world’s fish species and are a hotspot of marine endemism. By properly protecting them, Australia will be supporting the maintenance of our global ocean heritage.

The finalisation of the Marine Parks Network remains a remarkable opportunity for the Australian government to strengthen the levels of Marine National Park Zone IUCN II protection and to do so on the back of strong evidence. In contrast, implementation of the government’s retrograde draft management plans undermines ocean resilience and would allow damaging activities to proceed in the absence of proof of impact, ignoring the fact that a lack of evidence does not mean a lack of impact. These draft plans deny the science-based evidence.

We encourage the Australian government to increase the number and area of Marine National Park IUCN II Zones, building on the large body of science that supports such decision-making. This means achieving a target of at least 30% of each marine habitat in these zones, which is supported by Australian and international marine scientists and affirmed by the 2014 World Parks Congress in Sydney and the IUCN Members Assembly at the 2016 World Conservation Congress in Hawaii.

You can read a fully referenced version of the science statement here, and see the list of signatories here.

Australia is falling short in its ability to monitor the climate, potentially leaving farmers and other groups unable to access crucial information about rainfall, droughts and floods, the Australian Academy of Science has warned.

A review of Australia’s climate science capability, released today, recommends that Australia needs to recruit an extra 77 full-time climate science staff over the next four years, on top of the current 420, to meet the demand for detailed weather and climate information.

Without these resources, Australia risks being unable to provide accurate information to those who need it, said UNSW oceanographer Trevor McDougall, who led the review.

That could include being unable to predict accurately the changes to rainfall patterns in farming regions such as the Murray-Darling Basin – with potentially serious consequences for farmers, Professor McDougall said.

Although the review says Australia is strong in some areas, such as studying extreme weather events, it identified several key shortcomings, particularly in climate modelling.

Australia is not keeping pace with efforts in the United States and Europe, which are developing fine-scale climate models covering their own regions.

“Other countries are not looking in detail at our country – we need to run those models ourselves,” Professor McDougall said.

“These requirements are brought into sharper focus when you consider that our country is potentially more exposed to the impacts of climate change than most developed nations.”

Julie Arblaster, an atmospheric scientist at Monash University and co-author of the review, said Australian climatologists do not have enough access to the supercomputing facilities needed to run advanced climate models. “We need to look at multiple models from all around the world, but at the moment there isn’t the funding available,” she said.

Former CSIRO climatologist Graeme Pearman said the lack of regional climate predictions could have real consequences for Australian communities.

“We are not in a position at this stage to be able to confidently anticipate the water resource issues within the [Murray-Darling] basin. This is an enormous economic issue for Australia; it’s the food basin of the country,” he said.

“It’s not something that you can use a global model to anticipate – you have to have detailed, high-resolution information about particular areas of the coastline,” he said.

Australia currently has 420 full-time equivalent positions in climate change science and monitoring, spread across CSIRO, the Bureau of Meteorology, the Institute of Marine Science, Geoscience Australia, and universities.

Federal environment minister Josh Frydenberg said the government “continues to make a significant financial investment” in climate research, citing the new CSIRO centre in Hobart, as well as a range of other initiatives.

The review sets out a range of options for implementing the suggested staffing increases, including giving overall responsibility to CSIRO or the Bureau of Meteorology, or creating an entirely new agency.

Professor McDougall said that the proposed four-year phase-in period would allow many of the roles to be filled by Australian researchers, rather than recruiting from overseas.

“My guess is that we would be able to recruit more than half from inside Australia – we have quite a good crop of people who are early in their career. There are also Australians working overseas, waiting for their opportunity to come back.”